added product getbyid function

api/modules/Catalog/Catalog.Application/Products/EventHandlers/ProductReadEventHandler.cs

@@ -0,0 +1,17 @@
+using FSH.WebApi.Catalog.Domain.Events;
+using Microsoft.Extensions.Logging;
+using MediatR;
+
+namespace FSH.WebApi.Catalog.Application.Products.EventHandlers;
+
+public class ProductReadEventHandler(ILogger<ProductReadEventHandler> logger) : INotificationHandler<ProductRead>
+{
+    public async Task Handle(ProductRead notification,
+        CancellationToken cancellationToken)
+    {
+        logger.LogInformation("handling product read domain event..");
+        await Task.FromResult(notification);
+        logger.LogInformation("finished handling product read domain event..");
+    }
+}
+

api/modules/Catalog/Catalog.Application/Products/Get/v1/GetProductHandler.cs

@@ -0,0 +1,28 @@
+using Microsoft.Extensions.DependencyInjection;
+using FSH.WebApi.Catalog.Domain.Exceptions;
+using FSH.Framework.Core.Persistence;
+using FSH.Framework.Core.Caching;
+using FSH.WebApi.Catalog.Domain;
+using MediatR;
+
+namespace FSH.WebApi.Catalog.Application.Products.Get.v1;
+public sealed class GetProductHandler(
+    [FromKeyedServices("catalog:products")] IReadRepository<Product> repository,
+    ICacheService cache)
+    : IRequestHandler<GetProductRequest, GetProductResponse>
+{
+    public async Task<GetProductResponse> Handle(GetProductRequest request, CancellationToken cancellationToken)
+    {
+        ArgumentNullException.ThrowIfNull(request);
+        var item = await cache.GetOrSetAsync(
+            $"product:{request.Id}",
+            async () =>
+            {
+                var productItem = await repository.GetByIdAsync(request.Id, cancellationToken);
+                if (productItem == null) throw new ProductItemNotFoundException(request.Id);
+                return new GetProductResponse(productItem.Id, productItem.Name, productItem.Description, productItem.Price);
+            },
+            cancellationToken: cancellationToken);
+        return item!;
+    }
+}

api/modules/Catalog/Catalog.Application/Products/Get/v1/GetProductRequest.cs

@@ -0,0 +1,8 @@
+using MediatR;
+
+namespace FSH.WebApi.Catalog.Application.Products.Get.v1;
+public class GetProductRequest : IRequest<GetProductResponse>
+{
+    public Guid Id { get; set; }
+    public GetProductRequest(Guid id) => Id = id;
+}

api/modules/Catalog/Catalog.Application/Products/Get/v1/GetProductResponse.cs

@@ -0,0 +1,2 @@
+namespace FSH.WebApi.Catalog.Application.Products.Get.v1;
+public sealed record GetProductResponse(Guid? Id, string Name, string? Description, decimal Price);

api/modules/Catalog/Catalog.Domain/Events/ProductRead.cs

@@ -0,0 +1,7 @@
+using FSH.Framework.Core.Domain.Events;
+
+namespace FSH.WebApi.Catalog.Domain.Events;
+public sealed record ProductRead : DomainEvent
+{
+    public Product? Product { get; set; }
+}

api/modules/Catalog/Catalog.Domain/Exceptions/ProductItemNotFoundException.cs

@@ -0,0 +1,10 @@
+using FSH.Framework.Core.Exceptions;
+
+namespace FSH.WebApi.Catalog.Domain.Exceptions;
+public sealed class ProductItemNotFoundException : NotFoundException
+{
+    public ProductItemNotFoundException(Guid id)
+        : base($"product with id {id} not found")
+    {
+    }
+}

api/modules/Catalog/Catalog.Infrastructure/CatalogModule.cs

@@ -19,6 +19,7 @@ public override void AddRoutes(IEndpointRouteBuilder app)
         {
             var productGroup = app.MapGroup("products").WithTags("products");
             productGroup.MapProductCreationEndpoint();
+            productGroup.MapGetProductEndpoint();
         }
     }
     public static WebApplicationBuilder RegisterCatalogServices(this WebApplicationBuilder builder)

api/modules/Catalog/Catalog.Infrastructure/Endpoints/v1/GetProductEndpoint.cs

@@ -0,0 +1,21 @@
+using FSH.WebApi.Catalog.Application.Products.Get.v1;
+using FSH.Framework.Infrastructure.Auth.Policy;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.AspNetCore.Http;
+using MediatR;
+
+namespace FSH.WebApi.Catalog.Infrastructure.Endpoints.v1;
+public static class GetProductEndpoint
+{
+    internal static RouteHandlerBuilder MapGetProductEndpoint(this IEndpointRouteBuilder endpoints)
+    {
+        return endpoints.MapGet("/{id:guid}", (Guid id, ISender mediator) => mediator.Send(new GetProductRequest(id)))
+                        .WithName(nameof(GetProductEndpoint))
+                        .WithSummary("gets product by id")
+                        .WithDescription("gets prodct by id")
+                        .Produces<GetProductResponse>()
+                        .RequirePermission("Permissions.Products.View")
+                        .MapToApiVersion(1);
+    }
+}